Introduction
Polycythemia Vera (PV) is a disorder in the bone marrow, which produces a higher volume of red blood cells than the normal production level. This increased production is termed as erythrocytosis. Polycythemia is a group of diseases called myeloproliferative neoplasms (MPN). Red blood cells carry oxygen to all parts of your body. When the RBC levels increases, the blood becomes very much vicious and doesn’t flow ordinarily through blood vessels.
Increased in blood thickness and reluctant flow of blood may put you at risk of developing blood clots and restrict oxygen to reach the heart, lungs, brain and other vital parts of the body. This can lead to heart attack, stroke, and blockage of blood flow into the lungs.
In some cases of Polycythemia Vera (PV), it is accompanied by too much production of WBC and platelets (Megakaryocyte). This abnormal production is due to the clone of hematopoietic stem cells with high sensitivity to the maturation of different growth factors.
Secondary polycythemia
Secondary polycythemia is not because of high production of RBC in the bone marrow. Kidney, lung, and severe heart diseases may also pose a reason for the increased RBC bone marrow and is called as secondary polycythemia. Treatment for this type is different from PV. You may have a treatment that is relevant to the causes of secondary polycythemia.
History
There are three eras in the history of PV.
First era: Vaquez in 1892 and Osler in 1903 were initially described the Polycythemia Vera, and the introduction of therapeutic phlebotomy (TP) was introduced during this period.
Second era: In 1939, diagnostic techniques were developed to distinguish the relative and absolute polycythemia.
Third era: Between 1967 and 1997, the efforts of the Polycythemia Vera Study Group (PVSG) led to the development of criteria for the diagnostic steps and the effects of cytoreductive therapies.
In 2005, the discovery of ‘JAK2V617F’ mutation marked the start of the fourth era of Polycythemia Vera. Discovery of JAK 2 gene improved the diagnostic steps
Epidemiology
Polycythemia Vera impacts barely hundreds of men than girls. The sickness is calculable to have an effect on about two people in step with the 100,000 in the trendy populace. It occurs most regularly in humans at 60 years recent but could have an effect on people of any age. It is very unusual for humans under 20.
Causes
- Patients with polycythemia Vera (PV) have a mutation called ‘JAK2V617F’ in their JAK2 gene of blood-forming cells. This mutation happens if the signaling pathway of JAK 2 (Janus kinase 2) gene becomes de-regulated but it is not inherited from parents.
- This mutation occurs in the hematopoietic stem cells but doesn’t occur in the sperms or egg of the parents.
- In very rare cases this mutation can occur in the egg or sperms of the parents, which later can be inherited to their offspring with a condition of an autosomal dominant pattern.
- In some cases, liver and spleen also tend to produce blood cells, during this period bone marrow becomes scarred and less potential to produce blood cells.
Risk factors of Polycythemia Vera
- Few kinds of research suggest that exposure to a chemical called benzene is at more risk of having PV. It is most commonly used chemicals in the petrol and rubber industry.
- Exposure to radiations such as high-intensity UV light and Gamma radiation.
- A family history of PV. Parents can pass the mutated gene (JAK 2) onto their children.
- Sex: Men are more prone to get PV than the women
- Age: People who are older than 60 years are more likely to develop PV
- Smoking and alcoholism put you at higher risk.
- Previous blood clots can develop into PV
- Disease conditions such as stroke and diabetes may also a serious risk factor for PV.
- High cholesterol
Symptoms
Polycythemia vera has wide range of symptoms. Sometimes no symptoms at all.
- Sweating especially during night time
- Head ache
- Dizziness or vertigo
- Shortness of breath
- High blood pressure than normal
- Reddening of skin
- Itching after a warm bath
- Blurred vision
- Bleeding or blood clots which leads to stroke sometimes
- Fatigue
- Joint pain due to swelling
- Unexpected weight loss
- Pain in enlarged spleen (left upper abdomen)
Reddening of skin
Complications of Polycythemia Vera
- Thrombosis
- Enlarged Spleen
- High Levels of Red Blood Cells
- Myelofibrosis
- Leukemia
- Painful swelling of joints
Diagnosis and test
Initially polycythemia vera is diagnosed after a routine complete blood count (CBC) test. It reveals in the increase of red blood cells and sometimes it may increase with white blood cells or platelets.
The physician identifies based on the symptoms and signs of polycythaemia vera. E.g. Redness to the complexion, blood clotting or an increase in the size of the spleen.
Common diagnostic tests for polycythaemia vera include:
Blood tests: Complete blood count test that identifies the increase in haemoglobin as well as white blood cells.
Bone marrow biopsy: Bone marrow biopsy is usually done and it reveals the excess of red blood cells and white blood cells. It involves taking the small sample of solid material from bone marrow.
Bone marrow biopsy
Low Erythropoietin Level
The analysis of red blood cells may also indicate the level of erythropoietin (hormone involved in red blood cell production)
Gene mutation analysis of red blood cells
You may have another blood test to look for a change in a gene called JAK2.
Treatment and medications
Treatment for PV aims to reduce your blood cells, control your symptoms and to prevent some other serious problems. The most common treatment are include as follows
Venesection
It is the procedure in which the amount of blood is removed from the bloodstream and reduces the number of blood cells from the blood. This procedure makes the blood to thinner and flow more easily. It is the first option for treating PV. Depend on your severity of condition; the amount of blood is drawn from the body.
Low dose aspirin
Your doctor may prescribe low dose aspirin to prevent the risk of blood clots (thrombosis); it works by preventing the platelets from sticking together to form blood clots all over the body. Aspirin can irritate your stomach lining which may result in pain or discomforts causing, such as nausea, loss of appetite and heart burns. This can be avoided by taking the aspirin with food or milk. Coated aspirin will reduce the discomfort and stomach upset, though it dissolves directly in the intestine. Avoid other drugs while taking aspirin, unless you are advised to do so by your doctor.
Medications to reduce blood cells
People with polycythaemia vera who are not helped by venesection, medications can help to treat polycythaemia. Medications used to treat such as hydroxyurea (Droxia, Hydrea) to control production of blood cells from bone marrow.
Interferon alpha is used for lower the blood cell production. People who are not cured by hydroxyurea, interferon can be used to treat polycythaemia vera.
Medications to destroy cancer cells
People who are not respond or who can’t take hydroxyurea. Ruxolitinib (Jakafi) can be used to treat polycythaemia vera. It helps the immune system to destroy cancer cells and improve some symptoms of polycythaemia vera.
Therapy to reduce itching
If you feel itching, your doctor may prescribe medications such as antihistamines, or recommend ultraviolet light treatment to get rid of your discomfort.
Prevention of Polycythemia Vera
There is no way to prevent polycythaemia vera. But you can reduce discomforts by doing treatments.